The invention relates to systems for supplying air and fuel to engines operating on a gaseous fuel.
The invention also relates to dual fuel engines wherein one of the fuels employed is a gaseous fuel.
In prior engine installations employing gaseous fuel, the pressure reducing regulators feed gas directly into a venturi in response to venturi vaccum. Such action required a large fuel nozzle in the venturi because the volume of gaseous fuel being mixed with air is about ten percent of the air flow. The large volume of the fuel flowing into the venturi also substantially reduced the venturi vacuum. To compensate for this, prior venturis were more restrictive than if gaseous fuel was not introduced into the venturi. The system disclosed hereinafter is believed to be a substantial improvement over such prior arrangements because the gaseous fuel does not enter the system at the venturi and because the balancing of the air flow and fuel flow as disclosed hereinafter maintains a more precise air-fuel ratio with consequent improvement in emission results.
Attention is directed to the following U.S. Pats.:
Bodine U.S. Pat. No. 2,409,611 issued Oct. 22, 1946; PA0 Ensign U.S. Pat. No. 3,068,085 issued Dec. 11, 1962; PA0 Ensign U.S. Pat. No. 3,068,086 issued Dec. 11, 1962; PA0 Spencer U.S. Pat. No. 3,215,132 issued Nov. 2, 1965.